Refractory material recovery method, washing system and use method of recovered refractory material

Abstract

The invention discloses a refractory material recovery method which comprises the following steps: step 1, grinding a recovered refractory material into powder particles, and collecting the obtained powder particles; 2, the powder particles obtained in the step 1 are washed with water through a water washing method, and washed powder particles are obtained after water washing; and step 3, drying the washed powder particles obtained in the step 2 to obtain the recycled refractory material. Wherein in the step 2, the content of harmful ions' K < + >, Na < + >, S < 2-> and Cl <-> 'in the washed powder particles is detected, and washing is finished after the content of the harmful ions reaches the standard. According to the refractory material recycling method, the refractory material can be recycled, and the recycled refractory material is doped into a new material to manufacture a new refractory material, so that the economic benefit of the recycled refractory material is improved.

Description

Technical Field

[0001] This invention relates to the field of refractory material recycling, specifically to a refractory material recycling method, a water washing system, and a method for using recycled refractory materials. Background Technology

[0002] The rotary kiln is the core equipment in cement production. Its refractory lining operates under extremely harsh conditions, including temperatures exceeding 1400℃, erosion from raw materials and fuels, and mechanical stress and wear caused by kiln rotation and clinker sliding. Under the combined effect of these factors, the refractory material gradually forms a chemically infiltrated layer, a high-temperature erosion layer, and structural cracks, ultimately leading to refractory failure. Typically, the lifespan of refractory material in the safety zone of a cement kiln is about 2-3 years, while that in the firing zone is only about 1 year. In the transition zone, where conditions are more volatile, the lifespan can be as short as 6-10 months. Therefore, the cement industry generates a huge amount of waste refractory material every year.

[0003] Currently, the conventional methods for handling these failed refractory materials are mainly downgrading and end-of-life disposal. End-of-life disposal involves crushing and grinding the waste refractory materials and then mixing them into raw materials in a small proportion; downgrading involves recycling the refractory materials and using them as low-grade refractory products. Therefore, the economic benefits of recycling refractory materials are currently low. Summary of the Invention

[0004] The purpose of this invention is to provide a method for recycling refractory materials, a water washing system, and a method for using the recycled refractory materials. This method can recycle refractory materials and mix them into new materials to produce new refractory materials, thereby improving the economic benefits of recycling refractory materials.

[0005] To achieve the above objectives, the present invention provides a method for recycling refractory materials, comprising: Step 1: Grind the recycled refractory material into powder particles and collect the obtained powder particles; Step 2: Wash the powder particles obtained in Step 1 with water to obtain washed powder particles. Step 3: Dry the water-washed powder particles obtained in Step 2 to obtain recycled refractory material; In step 2, the harmful ions "K" in the washed powder particles are removed. + Na + S2 - Cl - The content of harmful ions was tested, and the washing process ended after the content of harmful ions met the standard.

[0006] Preferably, in step 1, the refractory materials are classified and different refractory materials are processed separately.

[0007] Preferably, a stepped water washing method is used in step 2.

[0008] Preferably, the water-to-solid mass ratio of the multi-stage washing is equal, and the water-to-solid mass ratio is (1~1.5):1.

[0009] Preferably, in step 1, the diameter of the powder particles is less than 5 mm, and more preferably, the diameter of the powder particles is 4.5 mm to 5 mm. In step 2, each wash should last at least 1 hour.

[0010] Preferably, in step 2, the concentration of harmful ions in the washed powder particles is detected after the fourth water wash, and a fifth water wash is determined based on the detection results.

[0011] The present invention also provides a water washing system for a refractory material recycling method, the water washing system comprising a primary water washing tank, a secondary water washing tank, a tertiary water washing tank, a quaternary water washing tank, and a backup water washing tank, wherein the backup water washing tank is provided with a free connection end, the free connection end being able to connect to any one of the primary water washing tank, the secondary water washing tank, the tertiary water washing tank, and the quaternary water washing tank.

[0012] The present invention also provides a method for using the recycled refractory material obtained by the refractory material recycling method, comprising: Step 1: Mix the recycled refractory material with the raw materials of new refractory material to obtain refractory material raw materials; Step 2: Use the refractory material raw materials obtained in Step 1 to make new refractory materials; In step 1, the recycled refractory material and the new refractory material belong to the same category of refractory material, and the recycled refractory material accounts for no more than 20% of the mass of the refractory material raw materials.

[0013] Preferably, the maximum particle diameter of the new refractory material raw material is 5-8 mm, and the mass percentage of the recycled refractory material raw material to the new refractory material raw material is 1:(4-11.5).

[0014] According to the above technical solution, this invention classifies and stores the recycled refractory materials according to their categories, processing only one type of waste refractory material at a time. First, a crusher is used to crush the recycled refractory materials. The resulting powder particles are then sieved to ensure that the particle size meets the requirements.

[0015] Before washing these powder particles with water, it is also necessary to test the specific composition of the refractory material before treatment to determine K. + Na + S2 - Cl -After washing, the specific composition of the washed powder particles is tested to determine whether the harmful ions meet the recycling standards. If not, the washing process continues until the harmful ions in the washed powder particles meet the recycling standards. The washed powder particles that meet the recycling standards are then dried to obtain recycled refractory material.

[0016] Refractory materials have specific requirements regarding the content of MgO, Al2O3, Fe2O3, CaO, SiO2, K2O, Cl, Na2O, and SO3. Multiple experiments have shown that during actual water washing, only K... + Na + S2 - Cl - The ion concentration of K+ is difficult to meet the requirements of refractory materials after water washing. Therefore, it is necessary to control the K+ concentration during the water washing process. + Na + S2 - Cl - The concentration of K ions is strictly controlled. Furthermore, K... + Na + These alkali metal ions significantly reduce the high-temperature properties of refractory materials, such as their softening point under load and creep resistance, resulting in poor thermal stability; SO4 2- Cl - These anions can react with other components in the batch, causing volume expansion, bubble formation, or corrosion of kiln furniture, affecting the structural strength and durability of the refractory material. Therefore, after washing, it is necessary to remove harmful ions "K" from the washed powder particles. + Na + S2 - Cl - The content of "" was tested, and the results were used to determine whether further washing was necessary.

[0017] The recycled refractory materials obtained are mixed into new raw materials to produce new refractory materials. Compared with downgrading and end-of-life disposal, the recycled refractory materials obtained by this method have higher economic benefits.

[0018] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart of a refractory material recycling method; Figure 2 This is a flowchart of a four-stage water washing process. Detailed Implementation

[0020] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0021] In this invention, unless otherwise stated, directional terms included in the terminology represent only the orientation of the term in its normal use or as commonly understood by those skilled in the art, and should not be regarded as a limitation on the term.

[0022] See Figure 1 The method for recycling refractory materials shown includes: Step 1: Grind the recycled refractory material into powder particles and collect the obtained powder particles; Step 2: Wash the powder particles obtained in Step 1 with water to obtain washed powder particles. Step 3: Dry the water-washed powder particles obtained in Step 2 to obtain recycled refractory material; In step 2, the harmful ions "K" in the washed powder particles are removed. + Na + S 2- Cl - The content of harmful ions was tested, and the washing process ended after the content of harmful ions met the standard.

[0023] By implementing the above technical solution, the recycled refractory materials are classified and stored according to their categories, and only one type of waste refractory material is processed at a time. First, a crusher is used to crush the recycled refractory materials, and the resulting powder particles are sieved to ensure that the particle size meets the requirements.

[0024] Before washing these powder particles with water, it is also necessary to determine the K content in the powder particles. + Na + S2 - Cl - After washing, the specific composition of the washed powder particles is tested to determine whether the harmful ions meet the recycling standards. If not, the washing process continues until the harmful ions in the washed powder particles meet the recycling standards. The washed powder particles that meet the recycling standards are then dried to obtain recycled refractory material.

[0025] Refractory materials have specific requirements regarding the content of MgO, Al2O3, Fe2O3, CaO, SiO2, K2O, Cl, Na2O, and SO3. Multiple experiments have shown that during actual water washing, only K... + Na + S2 - Cl - The ion concentration of K+ is difficult to meet the requirements of refractory materials after water washing. Therefore, it is necessary to control the K+ concentration during the water washing process. + Na + S2 - Cl - The concentration of K ions is strictly controlled. Furthermore, K... + Na + These alkali metal ions significantly reduce the high-temperature properties of refractory materials, such as their softening point under load and creep resistance, resulting in poor thermal stability; SO4 2- Cl - These anions can react with other components in the batch, causing volume expansion, bubble formation, or corrosion of kiln furniture, affecting the structural strength and durability of the refractory material. Therefore, after washing, it is necessary to remove harmful ions "K" from the washed powder particles. + Na + S2 - Cl - The content of "" was tested, and the results were used to determine whether further washing was necessary.

[0026] The recycled refractory materials obtained are mixed into new raw materials to produce new refractory materials. Compared with downgrading and end-of-life disposal, the recycled refractory materials obtained by this method have higher economic benefits.

[0027] Preferably, a belt dryer is used to dry the washed powder particles using waste heat from the cement plant, or the washed powder particles can also be dried by air drying.

[0028] Preferably, parameters such as the amount of water used for washing and the duration of washing are adjusted according to the specific composition of the refractory material before treatment to ensure that the treated refractory material is qualified.

[0029] Preferably, when manually sorting waste refractory materials, refractory materials with severe clinker adhesion and penetration need to be removed.

[0030] In this embodiment, preferably, in step 1, the refractory materials are classified and different refractory materials are processed separately.

[0031] In this embodiment, preferably, a stepped water washing method is used in step 2.

[0032] In one embodiment, the recycled refractory material can be treated using a four-stage stepped water washing method, such as... Figure 2 As shown.

[0033] The recovered refractory materials undergo a series of washing processes: a first-stage washing, a second-stage washing, a third-stage washing, and a fourth-stage washing. In the fourth-stage washing, clean water is used, and the resulting solids are filtered. The filtered solids are the washed powder particles. The filtered liquid is used as the fourth-stage water input to the third-stage washing to wash the solids from the second-stage washing. After the third-stage washing, the mixed liquid is filtered, and the filtered solids are input to the fourth-stage washing, while the filtered liquid is input to the second-stage washing. In the second-stage washing, the liquid filtered from the third-stage washing is used to wash the solids from the first-stage washing. After washing, the mixed liquid is filtered, and the filtered liquid is input to the first-stage washing. The filtered solids are input to the third-stage washing. In the first-stage washing, the liquid filtered from the second-stage washing is used to wash the recovered refractory powder particles. The mixed liquid after washing is filtered, and the filtered solids are input to the second-stage washing, while the filtered liquid is sent to wastewater treatment equipment.

[0034] Preferably, the washing time is set to be the same for each wash, thus enabling continuous washing of the powder particles. Each washing tank contains powder particles that need to be washed, and these particles continuously move to the next washing tank. The liquid filtered from the next washing tank continuously moves to the previous washing tank. This method enables continuous operation of the washing process and improves the washing efficiency of the recycled refractory materials.

[0035] This stepped washing process allows the cleanest water to contact the material with the lowest impurity content, which is about to be washed, while the high-concentration washing liquid contacts the newly added raw material with the highest impurity content. This counter-current flow creates the maximum impurity concentration difference at each stage, greatly enhancing the driving force for ion diffusion from the solid phase to the liquid phase, achieving the goal of minimizing water consumption and maximizing washing efficiency. The counter-current design significantly reduces water consumption, saving at least 50% of water.

[0036] The wastewater obtained after the first-stage washing and filtration is high-concentration wastewater. This high-concentration wastewater is collected separately, and its small volume facilitates subsequent treatment such as chemical precipitation and evaporation crystallization. Preferably, this high-concentration wastewater can be discharged into the kiln ash washing system, which achieves near-zero wastewater discharge and recovery of valuable salts, reducing the environmental pressure on the project.

[0037] In one embodiment, the water-to-solid mass ratio is equal in each stage of water washing, so that the liquid obtained after the subsequent stage of water washing and filtration can be directly input into the water washing tank of the previous stage.

[0038] In this embodiment, preferably, the water-to-solid mass ratio of the multi-stage water washing is equal, and the water-to-solid mass ratio is (1~1.5):1.

[0039] Preferably, the water-to-solid mass ratio of the last-stage washing tank can be set to a relatively large value so that the clean water added in the last-stage washing can still meet the water-to-solid mass ratio requirement of the first-stage washing tank when it finally enters the first-stage washing tank.

[0040] In this embodiment, preferably, in step 1, the diameter of the powder particles is less than 5 mm, and more preferably, the diameter of the powder particles is 4.5 mm-5 mm. In step 2, each wash should last at least 1 hour.

[0041] Comparative Example 1 1. Take the crushed silicon-mullite bricks, magnesium-aluminum bricks, and magnesium-iron bricks, and grind them into granules. Use a 10mm sieve to sieve these granules separately to obtain 1kg of each of silicon-mullite brick, magnesium-aluminum brick, and magnesium-iron brick granules with particles smaller than 10mm. 2. The silicon-mullite brick, magnesium-aluminate brick and magnesium-iron brick powder obtained in step 1 were subjected to three-stage countercurrent water washing. The water-to-solid mass ratio used in each stage of the water washing process was 1:1.5. The agitator speed was 180 rpm / min, the total processing time was 2 hours, and the processing time for each stage of water washing was the same.

[0042] The elemental contents in the process and in the final solid particles are shown in Table 1: Table 1:

[0043] Comparative Example 2 The method was carried out in accordance with Comparative Example 1, except that a 6mm sieve was used to sieve the powdered particles separately, resulting in 1kg of each of silicon-mullite brick, magnesium-aluminate brick, and magnesium-iron brick powdered particles smaller than 6mm.

[0044] The content of each element in the process and in the final solid particles is shown in Table 2.

[0045] Table 2:

[0046] Example 1 1. Take the crushed silicon-mullite bricks, magnesium-aluminum bricks, and magnesium-iron bricks, and grind them into granules. Use a 5mm sieve to sieve these granules separately to obtain 1kg of each of silicon-mullite brick, magnesium-aluminum brick, and magnesium-iron brick granules with particles smaller than 5mm. 2. The silicon-mullite brick, magnesium-aluminate brick and magnesium-iron brick powder obtained in step 1 were subjected to three-stage countercurrent water washing. The water-to-solid mass ratio used in each stage of the water washing process was 1:1.5. The agitator speed was 180 rpm / min, the total processing time was 2 hours, and the processing time for each stage of water washing was the same.

[0047] The content of each element in the process and in the final solid particles is shown in Table 3.

[0048] Table 3:

[0049] Example 2 The method of Example 1 was implemented, except that a 4.75mm sieve was used to sieve the powdered particles separately, resulting in 1kg each of silicon-mullite brick, magnesium-aluminum brick, and magnesium-iron brick powdered particles smaller than 4.75mm.

[0050] The content of each element in the process and in the final solid particles is shown in Table 4.

[0051] Table 4:

[0052] Example 3 The method of Example 1 was implemented, except that a 4.5mm sieve was used to sieve the powdered particles separately, resulting in 1kg each of silicon-mullite brick, magnesium-aluminate brick, and magnesium-iron brick powdered particles smaller than 4.5mm.

[0053] The content of each element in the process and in the final solid particles is shown in Table 5.

[0054] Table 5:

[0055] Example 4 1. Take the crushed silicon-mullite bricks, magnesium-aluminum bricks, and magnesium-iron bricks, and grind them into granules. Use a 5mm sieve to sieve these granules separately to obtain 1kg of each of silicon-mullite brick, magnesium-aluminum brick, and magnesium-iron brick granules with particles smaller than 5mm. 2. The silicon-mullite brick, magnesium-aluminate brick and magnesium-iron brick powder obtained in step 1 were subjected to three-stage countercurrent water washing. The water-to-solid mass ratio used in each stage of the water washing process was 1:1. The agitator speed was 180 rpm / min, the total processing time was 2 hours, and the processing time for each stage of water washing was the same.

[0056] The elemental contents in the process and in the final solid particles are shown in Table 6: Table 6:

[0057] Example 5 The method of Example 4 was implemented, except that a 4.75mm sieve was used to sieve these grinding particles separately, and 1kg of each of silicon-mullite brick, magnesium-aluminum brick and magnesium-iron brick grinding particles with a particle size of less than 4.75mm was obtained.

[0058] The elemental contents in the process and in the final solid particles are shown in Table 7.

[0059] Table 7:

[0060] Example 6 The method of Example 4 was implemented, except that a 4.5mm sieve was used to sieve these ground particles separately to obtain 1kg each of silicon-mullite brick, magnesium-aluminum brick and magnesium-iron brick ground particles with a particle size of less than 4.5mm.

[0061] The content of each element in the process and in the final solid particles is shown in Table 8.

[0062] Table 8:

[0063] Example 7 1. Take the crushed silicon-mullite bricks, magnesium-aluminum bricks, and magnesium-iron bricks, and grind them into granules. Use a 5mm sieve to sieve these granules separately to obtain 1kg of each of silicon-mullite brick, magnesium-aluminum brick, and magnesium-iron brick granules with particles smaller than 5mm. 2. The silicon-mullite brick, magnesium-aluminate brick and magnesium-iron brick powder obtained in step 1 were subjected to three-stage countercurrent water washing. The water-to-solid mass ratio used in each stage of the water washing process was 1:1. The agitator speed was 180 rpm / min, the total processing time was 1 hour, and the processing time for each stage of water washing was the same.

[0064] The content of each element in the process and in the final solid particles is shown in Table 9.

[0065] Table 9:

[0066] Example 8 The method of Example 7 was implemented, except that a 4.75mm sieve was used to sieve the powdered particles separately, and 1kg of each of silicon-mullite brick, magnesium-aluminum brick and magnesium-iron brick powdered particles smaller than 4.75mm were obtained.

[0067] The content of each element in the process and in the final solid particles is shown in Table 10.

[0068] Table 10:

[0069] Example 9 The method of Example 7 was implemented, except that a 4.5mm sieve was used to sieve the powdered particles separately, and 1kg of each of silicon-mullite brick, magnesium-aluminate brick and magnesium-iron brick powdered particles smaller than 4.5mm was obtained.

[0070] The content of each element in the process and in the final solid particles is shown in Table 11.

[0071] Table 11:

[0072] A comparison of Comparative Examples 1-2 and Examples 1-3 shows that when the particle size of the recycled refractory material is greater than 5 mm, the content of various harmful ions significantly exceeds the acceptable range after three-stage countercurrent water washing. Taking K2O as an example, when the particle size of the recycled refractory material is less than 10 mm, water washing can only remove about 30% of K ions; when the particle size of the recycled refractory material is less than 6 mm, the removal rate of K ions in silica-mullite bricks is about 30%, and the removal rate of K ions in magnesia-iron bricks and magnesia-alumina bricks is about 60%; when the particle size of the recycled refractory material is less than 5 mm, the removal rate of K ions in silica-mullite bricks is about 45%, and the removal rate of K ions in magnesia-iron bricks and magnesia-alumina bricks is about 77%. Therefore, fine grinding of recycled refractory materials can improve the removal effect of ions during the water washing process.

[0073] Comparative examples 1-9 show that when a 4.5-5mm sieve is used to screen the powdered material, a water-to-solid ratio of 1:1 can achieve good removal of harmful ions and further shorten the washing time to 1 hour. Preferably, changing the three-stage washing to a four-stage washing with a water-to-solid ratio of 1:1 is expected to achieve a washing process with better economic benefits.

[0074] In this embodiment, preferably, in step 2, the concentration of harmful ions in the washed powder particles is detected after the third water wash, and a fourth water wash is determined based on the detection results.

[0075] Normally, after four water washings, the content of harmful ions in the solid particles can meet the quality requirements for recycled refractory materials. However, after four water washings, the content of some harmful ions may still be too high. In this case, it is necessary to continue washing the solid obtained from the fourth water washing filtration. Preferably, a spare water washing tank is set up. In the spare water washing tank, the powder particles that fail the fourth water washing are washed for the fifth time. After the water washing is completed, the content of harmful ions is tested. If it fails, it needs to be washed again in the spare water washing tank until it meets the requirements.

[0076] Most of the washing operations for recycled refractory materials are completed through a production line from the first washing tank to the fourth washing tank. Materials that cannot meet the requirements after four washings are sent to a backup washing tank for offline processing. Therefore, setting up a backup washing tank can improve the washing efficiency.

[0077] The present invention also provides a water washing system for a refractory material recycling method. The water washing system includes a primary water washing tank, a secondary water washing tank, a tertiary water washing tank, a quaternary water washing tank, and a backup water washing tank. The backup water washing tank is provided with a free connection end, which can be connected to any one of the primary water washing tank, the secondary water washing tank, the tertiary water washing tank, and the quaternary water washing tank.

[0078] If the concentration of harmful ions in the washed powder particles is found to be substandard after the fourth wash, the backup washing tank can be used to continue washing the powder particles with clean water. After washing, the mixed liquid in the backup washing tank is filtered, and the filtered solid is used as the washed powder particles for the next drying step. In one embodiment, the filtered liquid can be used instead of clean water to be input into the third-stage washing tank; in another embodiment, the filtered liquid can also be returned to the backup washing tank for storage. The stored water can be used to replenish the first-stage, second-stage, and third-stage washing tanks, or it can be used for the next wash of the third substandard washed powder particles.

[0079] This invention also provides a method for using recycled refractory materials obtained from a refractory material recycling method, comprising: Step 1: Mix the recycled refractory material with the raw materials of new refractory material to obtain refractory material raw materials; Step 2: Use the refractory material raw materials obtained in Step 1 to make new refractory materials; In step 1, the recycled refractory material and the new refractory material belong to the same category of refractory material, and the recycled refractory material accounts for no more than 20% of the mass of the refractory material raw materials.

[0080] Incorporating recycled refractory materials into the raw materials for new refractory materials greatly improves the economic efficiency of recycled refractory materials.

[0081] Weigh all raw materials strictly according to the designed formula, dry mix them evenly in a mixer, then add a fixed amount of binder and wet mix until a plastic state is reached.

[0082] Standard specimens were produced by pressing them under constant pressure using the same mold and press.

[0083] After drying under identical conditions, all samples were placed in a kiln and fired according to the same firing curve. Taking silicon-mullite bricks as an example, recycled silicon-mullite brick materials were mixed with new silicon-mullite brick raw materials to produce silicon-mullite bricks, and the properties of the produced silicon-mullite bricks were tested to complete the following experiments.

[0084] Comparative Example 1 a. Use a 4.75mm sieve to screen the recycled refractory material particles. After these recycled refractory material particles are washed with water and qualified, they are used to obtain recycled refractory material raw materials. b. The new refractory material raw material is crushed to obtain crushed new refractory material raw material, without screening the crushed new refractory material raw material; c. Mix the recycled refractory material obtained in steps a and b with the new refractory material at a mass ratio of 1:9, and use the mixture to make refractory bricks.

[0085] The resulting refractory bricks have a loose structure and fail to meet performance standards.

[0086] Comparative Example 2 The method was implemented according to Comparative Example 1, except that the recycled refractory raw materials were mixed with the new refractory raw materials at a mass ratio of 1:19.

[0087] The refractory bricks produced meet the performance requirements of refractory materials.

[0088] Comparative Example 3 The method was implemented according to Comparative Example 1, except that no recycled refractory material raw materials were added, and all refractory bricks were made from new refractory material raw materials.

[0089] The refractory bricks produced meet the performance requirements of refractory materials, and their performance is better than that of Comparative Example 2.

[0090] Example 10 a. Use a 4.75mm sieve to screen the recycled refractory material particles, and wash these recycled refractory material particles with water to obtain recycled refractory material raw materials after they pass the water washing. b. Use a 10mm sieve to screen the new refractory material raw materials; c. Mix the recycled refractory material obtained in steps a and b with the new refractory material at a mass ratio of 1:4, and use the mixture to make refractory bricks.

[0091] The refractory bricks produced have weak areas, but their performance is basically satisfactory.

[0092] Example 11 The method of Example 11 was implemented, except that an 8mm sieve was used to screen the new refractory material raw materials.

[0093] The resulting refractory bricks have a dense structure and meet performance standards.

[0094] Example 12 The method of Example 11 was implemented, except that a 6mm sieve was used to screen the new refractory material raw materials.

[0095] The high bulk density of the mixed materials in step c results in a dense refractory brick structure with excellent overall performance.

[0096] Example 13 The method of Example 11 was implemented, except that a 5mm sieve was used to screen the new refractory material raw materials.

[0097] In step c, the overall particle system of the mixed material is relatively fine. Although the performance of the refractory brick meets the requirements, the porosity is slightly high.

[0098] Example 14 The method of Example 11 was implemented, except that a 4mm sieve was used to screen the new refractory material raw materials.

[0099] In step c, the overall particle system of the mixed material is too fine, requiring more binder, and the performance of the sintered refractory bricks is slightly inferior to the performance requirements of refractory bricks.

[0100] The comparison of proportions 1-3 shows that if the particle size of the new refractory raw materials is not specified, the proportion of recycled refractory raw materials must be reduced in order to produce refractory bricks with satisfactory performance. This leads to a decrease in the utilization rate of recycled refractory materials and is not conducive to the high-value recycling and utilization of recycled refractory materials.

[0101] Preferably, when the maximum particle diameter of the new refractory material raw material is 5-8 mm, the proportion of recycled refractory material can reach 20%, ensuring that the performance of the refractory bricks meets the requirements. However, when the maximum particle diameter of the new refractory material raw material is 4 mm, the performance of the refractory bricks produced will be slightly lower than that when the particle diameter is 5-8 mm.

[0102] In this embodiment, preferably, the particle diameter of the new refractory material raw material is 5-8 mm, and the mass percentage of recycled refractory material in the refractory material raw material is 1:(4-11.5).

[0103] Example 15 a. Use a 4.75mm sieve to screen the recycled refractory material particles. After these recycled refractory material particles are washed with water and qualified, they are used to obtain recycled refractory material raw materials. b. Use a 6mm sieve to screen the new refractory material raw materials; c. Mix the recycled refractory material obtained in steps a and b with the new refractory material at a mass ratio of 1:11.5, and use the mixture to make refractory bricks.

[0104] The resulting refractory bricks have low impurity accumulation and excellent performance.

[0105] Example 16 The method of Example 15 was implemented, except that the recycled refractory material raw material and the new refractory material raw material were mixed at a mass ratio of 1:9.

[0106] The resulting refractory bricks exhibited excellent performance, almost reaching the performance of the refractory bricks prepared in Comparative Example 3.

[0107] Example 17 The method of Example 15 was implemented, except that the recycled refractory material raw material and the new refractory material raw material were mixed at a mass ratio of 1:5.

[0108] The refractory bricks produced basically meet the performance requirements of refractory bricks.

[0109] Example 18 The method of Example 15 was implemented, except that the recycled refractory material raw material and the new refractory material raw material were mixed at a mass ratio of 1:3.

[0110] The refractory bricks produced do not meet the performance requirements of refractory bricks in some aspects.

[0111] Example of detection:

[0112] The performance requirements for silica-mullite bricks are as follows: room temperature compressive strength (MPa) not less than 90.0; apparent porosity (%) not greater than 16.0; load softening temperature T0.6 (°C) not less than 1680.

[0113] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0114] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0115] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for recycling refractory material, characterized by, The application relates to a recycling method of refractory materials. Step 1: grinding the recycled refractory materials into powder particles, and collecting the powder particles; Step 2: washing the powder particles obtained in step 1 by using a water washing method, and obtaining washed powder particles after the water washing; Step 3: drying the washed powder particles obtained in step 2, and obtaining recycled refractory materials. In step 2, the content of harmful ions "K + , Na + , S2 - , Cl - " in the water-washed powder particles is detected, and the water washing is ended after the content of the harmful ions reaches the standard.

2. The refractory material recycling method according to claim 1, characterized in that, In step 1, the refractory materials are classified, and different refractory materials are treated respectively.

3. The refractory material recycling method according to claim 2, characterized in that, In step 2, a step-by-step water washing method is used.

4. The refractory material recycling method according to claim 3, characterized in that, The water-solid mass ratio in the multi-stage water washing is equal, and the water-solid mass ratio is (1-1.5):

1.

5. The refractory material recycling method according to claim 4, characterized in that, In step 1, the diameter of the powder particles is less than 5 mm, preferably, the diameter of the powder particles is 4.5 mm-5 mm. In step 2, the water washing time is not less than 1 h.

6. The refractory material recycling method according to claim 2, wherein In step 2, the harmful ion concentration of the washed powder particles is detected after the fourth water washing, and whether the fifth water washing is needed is determined according to the detection result.

7. A water washing system used in the method of recycling a refractory material according to claim 6, characterized by, The water washing system comprises a first water washing tank, a second water washing tank, a third water washing tank, a fourth water washing tank and a standby water washing tank, the standby water washing tank is provided with a free connection end, and the free connection end can be connected with any one of the first water washing tank, the second water washing tank, the third water washing tank and the fourth water washing tank.

8. A method for using the recycled refractory material obtained by the method for recycling the refractory material according to any one of claims 1 to 6, characterized by, The application relates to a recycling method of refractory materials. Step 1: mixing the recycled refractory materials with raw materials of new refractory materials to obtain refractory material raw materials; Step 2: using the refractory material raw materials obtained in step 1 to prepare new refractory materials; In step 1, the recycled refractory materials and the new refractory materials belong to the same type of refractory materials, and the mass percentage of the recycled refractory materials in the refractory material raw materials is not more than 20%.

9. The method of using recycled refractory material of claim 8, wherein, The maximum particle diameter of the new refractory material raw materials is 5-8 mm, and the mass percentage of the recycled refractory material raw materials to the new refractory material raw materials is 1:(4-11.5).

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